AI Phone - Senior Agent Runtime Engineer

Overview

Build the execution infrastructure for AI agents at Bjak, a company reimagining the phone as proactive, intuitive, intelligent and low cost.

What you'll do

• Implement agent runtime and orchestration components.
• Build tool-calling and execution interfaces.
• Support multi-step and long-running task execution.
• Manage task state, execution history and asynchronous workflows.
• Implement error handling, retries and recovery mechanisms.
• Integrate multiple model providers.
• Build observability and tracing for agent execution.
• Optimize latency, reliability and inference costs.
• Work with context and memory components to provide relevant information to agents.

What you'll need

• Strong backend engineering experience.
• Experience with distributed systems and asynchronous workflows.
• Experience integrating LLMs into production applications.
• Strong API and service architecture knowledge.
• Experience with queues, state management and observability.
• Good understanding of tool calling and structured outputs.

Nice to have

• Production agent framework or custom agent runtime experience.
• Experience with Temporal or similar workflow orchestration systems.
• Experience with model routing and inference optimization.
• Experience with AI evaluation and tracing.